In a Patent Literature 1 listed below, disclosed is a seal structure for achieving gas-sealing between cells on an outer circumferential side of an electric power generation portion including an electrolyte, a fuel electrode and an air electrode in a solid oxide fuel cell that is configured by stacking plural cells with separators interposed therebetween.
In the seal structure of the Patent Literature 1, depressed portions and protruded portions that mesh with each other at a portion on the outer circumferential side from the electric power generation portion are provided between separators adjacent to each other, and a bitten thin sheet are disposed between the depressed portions and protruded portions. On both surfaces of the bitten thin sheet, glass seal pastes are pasted.
In this case, even if a dimension of a cell(s) or the like decreases when the fuel cell is operated for a long time under a high temperature environment, the bitten thin sheet gradually deforms by being pushed by the depressed portions and the protruded portions due to a force generated at that time, and thereby a gas seal performance can be ensured.